The invention relates to high pressure diaphragm test cells and more particularly to a clamping arrangement for securing the cell components together to resist high pressures.
High pressure membrane or diaphragm test cells serve for the filtration or for the inverted osmosis (in short, for the processing) of liquids under pressure in the area of 100 bar. They serve especially for use in the laboratory for testing of separating membranes or for the experimental preparations or model processings of liquids. Customarily such test cells have an upper part and a lower part. In the upper part, there is a pressure chamber for the medium that is to be processed. Furthermore, the upper part has an inlet for the medium that is to be processed and an outlet for the substance that is retained. Sometimes additional structure is provided in the upper part of the cell. In the lower part of the cell, there customarily is a filter support and the filter which, in most cases, is a multilayer filter; and possibly sealing elements are provided. Moreover, the lower part has a drainage mechanism for the permeate. Upper part and lower part are customarily made of high grade stainless steel and correspondingly have considerable weight.
In connection with such cells, it is important that the upper part and the lower part of the cell should be released as easily as possible from one another, as well as connected with one another in a high pressure sealing manner, with few manipulations.
For connecting the cell parts, wedge flange connections with bipartite clamping rings have particularly proven themselves. Such a wedge flange clamping closure has been known for example from German utility patent No. 72 25 662. In particular, on the lower part and on the upper part of the cell, wedge flanges are provided which may be forced against one another by a bipartite clamping ring having a trapezoid spaced ring groove. The parts of the ring surround the cell flanges so that the ring groove wedges the flanges together. The clamping of the ring parts is produced by two tightening screws situated tangentially relative to the clamp parts.
It is disadvantageous in the case of heretofore known devices employing such closing mechanism that after releasing of the tightening screws by means of an auxiliary tool, the wedged parts of the clamping ring must be forced apart and the cell then falls apart into three or four individual parts, namely into the upper cell part, the lower cell part and the two parts of the clamping ring. For the opening and closing of the cell which takes place several times daily in the laboratory, therefore, the cooperation of a plurality of persons is required for this operation if damage to the cell is to be avoided.
In the case of one previously proposed cell arrangement, one of the two parts of the clamping ring is mounted on a rear support wall. Even in the case of this arrangement, however, more than two hands are required to prevent the lower part from falling during the releasing of the tightening screws and the forcing away of the front part of the tightening ring.
Furthermore, pressure filtration cells have been known which have an upper part, a lower part and clamping elements interconnecting the two parts releasably. These pressure filtration devices are supported with their lower part on tripods. After the release of the clamping elements, a falling apart of the cell will be avoided through the fact that the upper part is still supported and carried just as it was before, by the lower part. It is disadvantageous in the case of opening of these cells however, that the upper part, which is connected with the discharge pipes and the supply pipes, usually pressure pipes, must be lifted from the lower part. This does not merely lead to inconveniences in the handling of the device but also presents inconveniences and limitations in the design of the pressure pipes.
In view of this status of the prior art, the present invention is based on the object of creating an apparatus for holding and closing the parts of a high pressure membrane test cell of the type previously discussed, which makes possible convenient and rapid handling of the cell by a single person and makes possible the use of rigid, locally fixed pressure lines in connection with the cell.